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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_4507_Библиотеки_им_академика_М_И_Перельмана.pdf
482
G. Tanyeri Toker et al.
gain ratio is 22:1. The ideal theoretical gain is 28dB.Normally, the middle ear gain
varies according to frequency and is often less than assumed. The average gain is
20dB between 250 and 500Hz and 25dB at 1000Hz and decreases by 6dB per
octave at higher frequencies [32].
The effects of ossiculoplasty on hearing mechanics are inuenced by factors
such as the hardness, weight, location, position, and tension of the reconstructed
ossicles, and their stability at both ends of the reconstruction. Reconstruction
materials typically meet the necessary criteria for hardness. In terms of weight,
a material weighing up to 16 times the weight of the stapes results in hearing
loss of less than 10dB [34]. For optimal results, the tympanic membrane/graft
should contact the posterosuperior quadrant, ensuring a material contact surface
of not less than 3–4mm in terms of location [35]. The angle between the material and the stapes should not exceed 45°, as excessive length may induce
unwanted tension and cause conductive hearing loss. However, there is no
objective method for measuring tension. Additionally, stability at both ends of
the material may not be achieved in the absence of a stapes head [32]. For optimal hearing results in stapedotomy, the diameter of the material used should be
at least 0.6mm [34]. When ossiculoplasty is performed, the continuity of the
ossicular chain can be achieved surgically; however, increasing the leverage
effect is not feasible [36].
24.4 Indications/Contraindications
Ossiculoplasty is a common procedure undertaken to address conductive hearing
loss caused by ossicular chain erosion secondary to prolonged inammation of
the middle ear. Approximately 45%–50% of patients exhibit an incus-long crus
defect as this ossicle is particularly vulnerable to ossicle erosion and has the
poorest blood supply [1]. The second most common erosion was observed in the
stapes, while the malleus was highly resistant to erosion. The indications and
Table 24.1 Indications and contraindications of ossiculoplasty
Indications Contraindications
Erosion or xation caused by cholesteatoma
and chronic otitis media (COM)
Ossicular chain defects (fracture/dislocation)
secondary to trauma [37]
Congenital anomalies (underdevelopment,
abnormal development, or xation of ossicles)
[38]
Otosclerosis Short life expectancy
Acute infection of the middle ear
Poor-cochlear reserve or sensorineural
hearing loss
The patient’s mental condition is bad enough
to make this hearing increase unnecessary
No results despite repeated operations
Having experienced prosthetic extrusion
many times
Irreversible dysfunction of the Eustachian
tube and/or middle ear mucosa
24 Ossiculoplasty
483
contraindications for ossiculoplasty are listed in Table24.1 [37, 38]. Although
the reconstruction performed for stapedial xation falls under the umbrella of
ossiculoplasty, it is often distinguished by terms such as stapes surgery, otosclerosis surgery, or stapedioplasty. If ossiculoplasty is contraindicated, offering a
hearing aid for auditory improvement becomes a prudent alternative. Additionally,
when considering surgery for a single or a well-hearing ear, reconstruction
options with a relatively low risk of cochlear damage should be preferred.
24.5 Reconstruction Materials
Autograft ossicles are considered the most ideal reconstruction material. However,
synthetic prostheses (70%), ossicles (25.1%), and cartilage (4.9%) are commonly
used [39]. The recommended primary material is autograft, but synthetic materials
have gained preference over the years. Notable examples include titanium prostheses, bone cement, and hydroxyapatite-Teon composite prostheses with titanium
necks. These materials can be summarized as follows:
1. Autografts (ossicles, cartilage, cortical bone, etc.)
2. Allografts (ossicles, cartilage, teeth, cortical bone, etc.)
3. Metals (gold, steel, platinum, titanium).
4. Polymers (plastipore, proplast, teon).
5. Ceramics (ceravital, bioglass, hydroxyapatite).
6. Alloplast materials (carbon-carbon, ionomeric cement).
The properties that an ideal reconstruction material should have been as follows:
1. Easy to nd.
2. Easy shaping and placement.
3. Biocompatibility.
4. Non-resorbable and non-xed.
5. Low extrusion rate.
6. Low cost.
7. Good and permanent result.
8. Compatibility with magnetic resonance imaging.
Each material has its advantages and disadvantages. These are summarized in
Table24.2 [40].
It can be seen from the table that the relatively most ideal reconstruction material is autograft ossicles. However, most authors reported that they used synthetic
prostheses (70%), ossicles (25.1%), and cartilage (4.9%), respectively [39]. As
the chapter authors, we think that the primary material should be autograft, but we
have tended to prefer synthetic materials over the years. These are titanium prostheses, bone cement, and hydroxyapatite-teon composite prostheses with titanium necks.
484
Table 24.2 Advantages and disadvantages of the materials used in ossicular chain
reconstruction
Advantage/disadvantage
Advantages Good and permanent result ++ +
Low extrusion rate ++ +
Easy to nd ++
Easy shaping
Biocompatibility ++ +
Lower costs ++
Disadvantages Limited use due to disease +
Preparation phase + +
Resorption
Fixation + + +
Morbidity at the donor site +
Disease transmission
Reaction/infection
*
Diseases such as AIDS, Jacob-Creutzfeldt, hepatitis etc.
*
Autograft Allograft Alloplast
−
+/− +/−
+/− − −
− − −
+/− +/− − −
− − −
−
− −
+
G. Tanyeri Toker et al.
Composite
+/−
+/−
+ +
+ +
+/− +/−
− −
− −
+ +
++
+
−
24.6 Evaluation ofthePatients
Patient History A comprehensive patient history is crucial. Patients usually present
with signs and symptoms of hearing loss, ear discharge, pain, dizziness, tinnitus, and
facial paresis/paralysis. When these symptoms appear, their relationship with time (i.e.,
whether they are intermittent or continuous), duration, association, and progression
should be explored. The patient’s general health status, coexisting conditions, medications used, and smoking status should be assessed. Understanding patient’s and physician’s expectations from surgery is essential to minimize postoperative issues.
Physical Examination During physical examinations, ear, nose, throat, head, and
neck examinations and systemic examinations should be performed, and the ndings should be noted. The condition of the auricle in the ear where the operation is
planned, including the presence of an incision or trauma scars, and the existence of
any congenital anomalies should be evaluated. The evaluation of the external ear
canal is important for determining the surgical approach. The diameter of the canal,
shape (straight or curved), and the presence of cerumen, debris, discharge, protruding lesions, or infections should be evaluated. Tympanic membrane examination is
also crucial. Given that the ears requiring ossiculoplasty are typically associated
with chronic otitis media (COM) cases, the tympanic membrane is usually perforated. However, in certain situations, such as COM sequelae, congenital ossicular
defects, and traumatic situations, the tympanic membrane may remain intact.
Retraction or adhesions may also occur. In the event of a perforation, the status of
the perforation and the tympanic cavity visible through the perforation should be
evaluated. In the presence of pathological tissue, the priority is to remove these tissues and ensure a well-ventilated tympanic cavity covered with dry, healthy mucosa.
If needed, the ossiculoplasty may be postponed until the second session.
24 Ossiculoplasty
485
Audiological Evaluation Before ossiculoplasty, pure-tone and speech audiometry
must be performed for medicolegal reasons. By determining the air and bone conduction thresholds, predictions can be made regarding the conditions of the ossicular chain, cochlear reserve, and hearing gain that can be expected following the
surgery. Information regarding the functional status of the opposite ear is obtained
for patient selection. If the tympanic membrane is intact, then tympanometry and
stapes reex tests are performed. In general, an air–bone gap of ≥30dB generally
indicates ossicular erosion or xation. However, pathological tissues, such as cholesteatoma, polyps, and granulation tissues, may mask real hearing loss by falsely
contributing to sound transmission.
For patients with tympanic membrane perforation and hearing loss, a patch test
could provide valuable insights. This test can be performed using a cigarette
paper, a soaked gel lm, or a thin piece of silastic cover. Although this test is often
neglected preoperatively, it is simple and useful. During the procedure, audiometry is initially performed. Then, the paper is closed over the perforation to simulate a scenario as if intact tympanic membrane was intact post-surgery.
Subsequently, a repeat audiometry is performed, yielding three possible outcomes: hearing thresholds may partially or completely improve, remain the same,
or worsen. When hearing thresholds recover completely or almost completely, it
is understood that the ossicular chain is normal, hearing loss is caused by perforation, and hearing will improve if the tympanic membrane perforation is repaired.
In other cases, the integrity or mobility of the ossicular chain is impaired owing to
ossicular xation, dislocation, or erosion; therefore, ossicular chain reconstruction is necessary.
Patients often misconstrue hearing loss as an inability to understand what they
hear (i.e., low discrimination). Therefore, speech audiometry should be performed
in patients undergoing ossiculoplasty. Evaluating the functional status of the contralateral ear is important for proper patient selection. If the tympanic membrane is
intact, tympanometry and stapes reex tests are performed. To preoperatively evaluate the eustachian tube function in the ear to be operated on and the opposite ear, the
Automated Williams Test (Eustachian Tube Function Test-1 [ETF-1]) and the
Automated Toynbee Test (Eustachian Tube Function Test-2 [ETF-2]) are routinely
performed.
Radiological Evaluation Advanced imaging techniques, such as computed
tomography and magnetic resonance imaging, should be performed to predict
possible pitfalls and medicolegal considerations. The indications for imaging
include (1) revision surgery, (2) hearing loss too profound to be explained by
examination ndings, (3) discrimination score lower than expected, and (4)
presence or suspicion of cholesteatoma. Some surgeons may consider radiological examinations as unnecessary when ossiculoplasty alone is performed. Other
surgeons, including the authors of this chapter, routinely order computed tomography to foresee possible pitfalls and to take precautions against medicolegal
problems.
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G. Tanyeri Toker et al.
Patient Selection and Information Patient selection is very important in ossiculoplasty, which is a functional surgery. It is very critical to determine which patients
should not be operated, not which patients should be operated. The important factors in this selection are as follows:
1. The age of the patient (it would be more appropriate to eliminate hearing loss
using hearing aids in patients over 65years of age).
2. General health and mental condition (ossiculoplasty is contraindicated in men-
tally retarded patients).
3. Presence of otic capsule anomaly.
4. Single ear or good hearing ear.
5. Functional status of the Eustachian tube.
6. The problem of ventilation of the tympanic cavity.
7. Postoperative hearing aid need in the presence of mixed hearing loss.
8. Whether enough hearing gain can be achieved to contribute to the comfort of life.
After the patient selection is made and the ossiculoplasty operation is decided, it
is both the duty of the surgeon and a legal obligation to inform the patient. For this
reason, the situations that should be explained to the patient and stated in detail in
the consent form are as follows:
1. Anesthesia technique.
2. Surgery.
(a) Technique.
(b) Duration.
(c) Postoperative.
(i) Possible complaints.
(ii) Recovery period.
(iii) Nature, number, and duration of care, dressing, and controls.
(iv) Lifestyle changes and restrictions.
(d) Success rate.
(e) Cost.
24.7 Surgical Preparation
Ossiculoplasty is a comprehensive surgical intervention for the tympanic cavity or
tympanomastoid surgery, trauma surgery, or anomaly surgery. Each surgeon should
access the tympanic cavity using his or her preferred approach according to his or
her experience. When performing ossiculoplasty, surgeons utilize their own modied techniques derived from basic approaches rather than relying on a standardized method.
Equipment The equipment required for ossiculoplasty are:
24 Ossiculoplasty
487
1. Operating microscope/endoscope.
2. Standard ear microsurgery set (Fig.24.2).
3. Reconstruction material.
4. Ossicle holder and drills for shaping (for autograft/allograft).
Surgical Imaging Although microscopes are still the main surgical imaging methods [41, 42], endoscopes can also be used in ossiculoplasty [43, 44]. Endoscopic
ossiculoplasty has been reported to provide better imaging and early audiological
outcomes than microscopic techniques, although the long-term audiological results
and the incidence of complications remain similar [45, 46]. A comparison of the two
methods is presented in Table24.3 [40].
Anesthesia Ossiculoplasty can be performed under intravenous (IV) sedation/
local anesthesia or general anesthesia, depending on whether other otological
procedures are planned. If tympanomastoidectomy is planned, ossiculoplasty
can be performed under general anesthesia. If the goal is to restore ossicular
continuity in an ear without any active disease, ossiculoplasty can be performed
under IV sedation or local anesthesia. As chapter authors, we prefer general
anesthesia. For individuals who prefer sedation, premedication is administered
30–60 min before surgery. Premedication options include peroral diazepam,
intramuscular 1–1.5 mg/kg pethidine (10 mg), and intramuscular 0.1 mg/kg
midazolam options.
Fig. 24.2 Standard (left) and instruments designed for endoscopic surgery (right) used in
ossiculoplasty
488
Table 24.3 Comparison of endoscopic and microscopic ossiculoplasty
Microscopic
Working in the narrow/curved EEC Difcult Easy
Number of working hands Both hands Single hand
The need for drilling More Less
Need for frequent cleaning None Present
Learning surgery Faster Slower
Image
Visual angle Narrow Wide
Zoom in New generation is good Good
Angled view None Possible
Depth perception/3D Good Not good
EEC external ear canal, 3D 3-dimensional
G. Tanyeri Toker et al.
Endoscopic
Inltration Anesthesia A mixture of 1:100,000 epinephrine and 1% lidocaine was
administered for anesthesia regardless of the chosen approach. However, the amount
and application area varied depending on the approach employed. In the retroauricular approach, inltration is performed into the incision line and external ear
canal quadrants by injecting the retroauricular region. The meatus is then opened
with a speculum, and inltration is applied to the anterior quadrant, then the upper
quadrant by entering between the tragus and the helix. In the transcanal approach,
only external ear canal inltration alone is sufcient.
24.8 Surgical Technique
Approaches As in other ear surgeries, ossiculoplasty can be performed through
three approaches. These are (1) Retroauricular (postauricular) approach, (2)
Endaural approach, and (3) Transcanal (endomeatal, transmeatal) approach. As the
authors of this chapter, we prefer the retroauricular approach when mastoid surgery
is required in the same session and the transcanal or endaural approach if mastoidectomy is not necessary. The endaural approach is favored if the use of a microscope
is needed owing to the presence of stenosis in the cartilaginous external ear canal.
Reaching the Tympanic cavity and Evaluation of the Cavity After incisions are
made according to this approach, a tympanomeatal ap is created and elevated to
reach the tympanic cavity. Important landmarks such as the chorda tympani, long
crus of the incus, stapes, stapes muscle tendon, round window niche, and cochleariform process are evaluated.
The condition of the cavity signicantly inuences ossiculoplasty success,
necessitating the identication and removal of mucosal abnormalities (edema and
hyperplasia) and pathological formations (polyps, granulation tissue, brotic bands,
and cholesteatoma). The existence of traps (such as vascular anomalies, carotid
canal dehiscence, high jugular bulb, persistent stapedial artery, fallopian canal
24 Ossiculoplasty
489
dehiscence, and wide cochlear aqueduct) should be considered, to prevent
complications.
Checking Ossicular Chain and Determination of the Defect Both the integrity
and mobility of the ossicular chain should be assessed. For this purpose, surgeons
should verify whether the movement can be transferred to the base of the stapes.
Furthermore, light movement should be observed in the round window niche. Even
if an ossicular defect is detected, the mobility of the other ossicles should be
evaluated.
The classication made by Austin and later modied by Kartush is commonly
utilized to categorize ossicular chain defects [11, 47]. Once the nature and size of
the defect are determined based on this classication, the most appropriate reconstruction method (see Reconstruction Methods) and material are selected.
Reconstruction Material Selection and Adjustment The selection of reconstruction materials is performed by considering the advantages and disadvantages
(Table 24.2). Synthetic materials with high biocompatibility should be preferred.
Direct contact of the synthetic prosthesis with the tympanic membrane or graft
should be avoided, with the cartilage placed in between.
Autograft ossicular repositioning is frequently performed during ossiculoplasty.
In such cases, the ossicle is converted into a suitable prosthesis. This step, inherently
susceptible to errors and time-consuming until surgeons accumulate experience,
typically requires a few minutes for completion. Using specially designed clamps,
such as Sheehy locked forceps or a small hemostatic clamp, the ossicle is carefully
held in place, while a small cutting-drilling tip is used for shaping the ossicle without causing thermal damage. The ossicle is usually shaped as a partial ossicular
replacement prosthesis, total ossicular replacement prosthesis (TORP), or partial
incus replacement prosthesis. When the incus is utilized as the ossicle and is positioned between the head of the stapes and manubrium, the long crus is cut.
Subsequently, a hole (acetabulum) is created on the short crus where the head of the
stapes will be. Simultaneously, a groove is made on the other side, where the manubrium will be. To reduce the risk of xation, the outer surface of the shaped ossicle
must be polished thoroughly. To establish a solid connection with the head of the
stapes, the interior of the open hole should not have a shiny surface but should
remain jagged. Retaining bone shavings in the hole may prove advantageous. If the
shaped ossicle is not intended to be positioned beneath the manubrium, the creation
of a groove is unnecessary; if it is not intended to be positioned on the head of the
stapes and is to be placed on the base of the stapes or on stapedotomy/stapedectomy,
the acetabulum should remain unopened.
If the malleus is chosen as the ossicle, the malleus head is adjusted such that it is
positioned under the tympanic membrane. The hole, located at the stapes head, is
opened toward the malleus neck. The malleus is shaped as TORP, with the tip of its
manubrium at the base of the stapes and its head under the tympanic membrane. On
490
G. Tanyeri Toker et al.
occasion, the ossicle can be shaped to serve as a partial incus replacement prosthesis
(e.g., the Applebaum prosthesis). In such instances, an acetabulum is created according to the stapes head, and a groove is created according to the long crus of the incus.
The length of the material should be slightly larger than the length of the space
between the medial and lateral elements, representing the space it will occupy. If the
reconstruction material is excessively long, the mobility of the ossicular chain can
be restricted due to excessive tension, potentially leading to ossicular fractures.
Conversely, reconstruction materials that are too small may fail to establish a connection between the medial and lateral elements and may not ensure the transmission of sound energy to the vestibule.
To ascertain the size of the reconstruction material, it is important to determine
two specic lengths: (1) the distance between the stapes head/base and malleus neck
and (2) the distance between the original tympanic annulus and medial ossicular
element. These distances play a critical role in ensuring the stabilization of the prosthesis and achieving optimal hearing gain. If the calculated distance is too large,
resulting in an unsafe, misaligned prosthesis, corrective measures can be implemented. This may involve the posterior relocation of the malleus, adjustment of the
manubrium posteriorly closer to the stapes, and the meticulous placement of the
prosthesis, ensuring a robust and stable reconstruction [48].
Reconstruction Following the preparation of the selected material for ossiculo-
plasty, reconstruction is performed. The overarching principle guiding this procedure, applicable to both autograft and synthetic materials, is the meticulous
adjustment of size and the appropriate placement of the reconstruction material. A
critical element in this process is ensuring that the material is positioned to generate
a subtle tension between the medial and lateral structures. The success of the postoperative outcome is contingent upon the stability of reconstruction materials during checks in the operating. The integrity, strength, and mobility of the new ossicular
chains created after reconstruction are assessed.
Reconstruction Methods The type of reconstruction performed on the ossicular
chain is determined based on the nature and size of the defects. Austin’s classication was initially utilized to assess the status of the ossicular chain and standardize
postoperative reporting and hearing results, which was subsequently modied by
Kartush [47].
Reconstruction options according to ossicular chain defects are presented in the
tables below (Tables 24.4, 24.5, 24.6, 24.7, 24.8 and 24.9) and pictures of the recon-
struction applied for the relevant defect (Figs.24.3, 24.4, 24.5, 24.6, 24.7, 24.8,
24.9, 24.10 and 24.11) are presented under each table.
Repositioning the Flap, Closing the Layers, and Buffering Following reconstruction, the tympanomeatal ap and any graft are carefully positioned in
place. To assess the stability of the reconstruction and its contact with the tympanic membrane/graft, the tympanomeatal ap is gently lifted, allowing for an
24 Ossiculoplasty
Table 24.4 Reconstruction options for incus defects
M+ I- S+ (Austin/Kartush A)
Lenticular process defect Long crus defect/no incus
Bone cement (Fig.24.3) Shaped incus interposition (Fig.24.4)
Shaped incus interposition PORP between malleus and stapes (Fig.24.5)
PORP PORP between tympanic membrane and stapes
Partial incus replacement
prosthesis
Shaped autograft cortical
bone transposition
M+I-S+ Malleus, present; incus, none; stapes, present
Table 24.5 Reconstruction options for incus and stapes defects
M+ I- S- (Austin/
Kartush B)
TORP
(Fig.24.7)
Shaped ossicular
transposition
Piston
(Fig.24.8)
M+I-S- Malleus, present; incus, none; stapes, none
If the stapes base is intact and mobile, reconstruction is performed between
the stapes base and the malleus or tympanic membrane. If the stapes base is
absent or xed, the reconstruction is performed between the vestibule and
the malleus or tympanic membrane.
Bone cement (Fig.24.6)
Separating the malleus from the tympanic membrane and
rotating it onto the head of the stapes (malleus relocation)
Shaped autograft cortical bone transposition
Incus replacement prosthesis
491
Table 24.6 Reconstruction
options for malleus and
incus defects
Table 24.7 Reconstruction options for malleus, incus and stapes defects
M- I- S- (Austin/Kartush D)
TORP (Fig.24.10) If the stapes base is absent or xed, the reconstruction is performed
Shaped ossicle or
cortical bone
transposition
Allograft tympanoossicular composite
graft
Double or triple
cartilage block
M-I-S- Malleus, none; incus, none; stapes, none
between the vestibule and the tympanic membrane; if the base is intact
and mobile, the reconstruction is performed between the stapes base
and the tympanic membrane.
M- I- S+ (Austin/Kartush C)
PORP (Fig.24.9)
Shaped ossicular transposition
Double or triple cartilage block depending on the depth of
the tympanic cavity
Allograft tympano-ossicular composite graft
M+I-S+ Malleus, present; incus, none; stapes, present